Poly[[tetraaqua(μ4-imidazole-4,5-dicarboxylato)(μ3-imidazole-4,5-dicarboxylato)-μ3-sulfato-μ2-sulfato-cobalt(II)digadolinium(III)] monohydrate]

Abstract

The asymmetric unit of the title compound, {[CoGd2(C5H2N2O4)2(SO4)2(H2O)4]·H2O}n, contains one CoII ion, two GdIII ions, two imidazole-4,5-dicarboxylate ligands, two SO42− anions, four coordinated water molecules and one uncoordinated water molecule. The CoII ion is six-coordinated by two O atoms from two coordinated water molecules, as well as two O atoms and two N atoms from two imidazole-4,5-dicarboxylate ligands, giving a slightly distorted octahedral geometry. Both GdIII ions are eight-coordinated in a distorted bicapped trigonal–prismatic geometry. One GdIII ion is coordinated by four O atoms from two imidazole-4,5-dicarboxylate ligands, three O atoms from three SO42− anions and a water O atom; the other GdIII ion is bonded to five O atoms from three imidazole-4,5-dicarboxylate ligands, two O atoms from two SO42− anions as well as a water O atom. These metal coordination units are connected by bridging imidazole-4,5-dicarboxylate and sulfate ligands, generating a heterometallic layer parallel to the ac plane. The layers are stacked along the b axis via N—H...O, O—H...O, and C—H...O hydrogen-bonding interactions, generating a three-dimensional framework.